Add a DumpTestUtils class to do service dumps in tests.

This allows tests to run dumpsys without worrying too much about
the nitty-gritty of finding the service, piping the output back,
etc.

Test: simple test added in other CL in topic
Change-Id: I0628c55ad199e4c888e4947e11bdb0a3b8150767
diff --git a/staticlibs/testutils/Android.bp b/staticlibs/testutils/Android.bp
index 133c983..2dda269 100644
--- a/staticlibs/testutils/Android.bp
+++ b/staticlibs/testutils/Android.bp
@@ -31,6 +31,7 @@
     ],
     static_libs: [
         "androidx.test.ext.junit",
+        "compatibility-device-util-axt",
         "kotlin-reflect",
         "libnanohttpd",
         "net-tests-utils-host-device-common",